Abstract: Objective To investigate the expression of Caspase-3 and bcl-xL in psoriatic lesional skin. Methods Immunohistochemical technique was employed to observe the expression of Caspase-3 and bcl-xl in the lesional skin and the perilesional skin with normal appearance in 26 patients with psoriasis vulgaris. Normal skin from 10 healthy persons was used as negative control. Results Caspase-3 was found in the normal skin, the lesional skin and the perilesional skin with normal appearance. Significantly increased expression was observed in the lesional epidermis (P<0.0001). Bcl-xL was not found in the normal skin and the perilesional skin with normal appearance, except a scattered expression in the lesional epidermis. Conclusion Caspase-3 and bcl-xL might be involved in the pathogenesis of psoriasis by inducing the apoptosis of epidermal keratinocytes.

Key words: Psoriasis, Caspases, Genes, bcl-2